期刊文献+
共找到1,355篇文章
< 1 2 68 >
每页显示 20 50 100
Ultrafast dynamics in photo-excited Mott insulator Sr_(3)Ir_(2)O_7 at high pressure
1
作者 尹霞 张建波 +6 位作者 王东 Takeshi Nakagawa 夏春生 张曹顺 郭伟程 昌峻 丁阳 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期149-155,共7页
High-pressure ultrafast dynamics,as a new crossed research direction,are sensitive to subtle non-equilibrium state changes that might be unresolved by equilibrium states measurements,providing crucial information for ... High-pressure ultrafast dynamics,as a new crossed research direction,are sensitive to subtle non-equilibrium state changes that might be unresolved by equilibrium states measurements,providing crucial information for studying delicate phase transitions caused by complex interactions in Mott insulators.With time-resolved transient reflectivity measurements,we identified the new phases in the spin–orbit Mott insulator Sr_(3)Ir_(2)O_7 at 300 K that was previously unidentified using conventional approaches such as x-ray diffraction.Significant pressure-dependent variation of the amplitude and lifetime obtained by fitting the reflectivity?R/R reveal the changes of electronic structure caused by lattice distortions,and reflect the critical phenomena of phase transitions.Our findings demonstrate the importance of ultrafast nonequilibrium dynamics under extreme conditions for understanding the phase transition of Mott insulators. 展开更多
关键词 ultrafast dynamics high pressure phase transition Mott insulator
下载PDF
Quantitative determination of the critical points of Mott metal–insulator transition in strongly correlated systems
2
作者 牛月坤 倪煜 +4 位作者 王建利 陈雷鸣 邢晔 宋筠 冯世平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期647-652,共6页
Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transiti... Mottness is at the heart of the essential physics in a strongly correlated system as many novel quantum phenomena occur in the metallic phase near the Mott metal–insulator transition. We investigate the Mott transition in a Hubbard model by using the dynamical mean-field theory and introduce the local quantum state fidelity to depict the Mott metal–insulator transition. The local quantum state fidelity provides a convenient approach to determining the critical point of the Mott transition. Additionally, it presents a consistent description of the two distinct forms of the Mott transition points. 展开更多
关键词 critical point metal–insulator transition local quantum state fidelity strongly correlated system quasiparticle coherent weight
下载PDF
Optical study of magnetic topological insulator MnBi_(4)Te_7
3
作者 廖知裕 沈冰 +1 位作者 邱祥冈 许兵 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期231-235,共5页
We present an infrared spectroscopy study of the magnetic topological insulator MnBi_(4)Te_7 with antiferromagnetic(AFM) order below the Neel temperature TN= 13 K. Our investigation reveals that the low-frequency opti... We present an infrared spectroscopy study of the magnetic topological insulator MnBi_(4)Te_7 with antiferromagnetic(AFM) order below the Neel temperature TN= 13 K. Our investigation reveals that the low-frequency optical conductivity consists of two Drude peaks, indicating a response of free carriers involving multiple bands. Interestingly, the narrow Drude peak grows strongly as the temperature decreases, while the broad Drude peak remains relatively unchanged. The onset of interband transitions starts around 2000 cm^(-1), followed by two prominent absorption peaks around 10000 cm^(-1) and 20000 cm^(-1). Upon cooling, there is a notable transfer of spectral weight from the interband transitions to the Drude response. Below TN, the AFM transition gives rise to small anomalies of the charge response due to a band reconstruction.These findings provide valuable insights into the interplay between magnetism and the electronic properties in MnBi_(4)Te_7. 展开更多
关键词 infrared spectroscopy magnetic topological insulator Drude model band reconstruction
下载PDF
Data augmentation method for insulators based on Cycle-GAN
4
作者 Run Ye Azzedine Boukerche +3 位作者 Xiao-Song Yu Cheng Zhang Bin Yan Xiao-Jia Zhou 《Journal of Electronic Science and Technology》 EI CAS CSCD 2024年第2期36-47,共12页
Data augmentation is an important task of using existing data to expand data sets.Using generative countermeasure network technology to realize data augmentation has the advantages of high-quality generated samples,si... Data augmentation is an important task of using existing data to expand data sets.Using generative countermeasure network technology to realize data augmentation has the advantages of high-quality generated samples,simple training,and fewer restrictions on the number of generated samples.However,in the field of transmission line insulator images,the freely synthesized samples are prone to produce fuzzy backgrounds and disordered samples of the main insulator features.To solve the above problems,this paper uses the cycle generative adversarial network(Cycle-GAN)used for domain conversion in the generation countermeasure network as the initial framework and uses the self-attention mechanism and channel attention mechanism to assist the conversion to realize the mutual conversion of different insulator samples.The attention module with prior knowledge is used to build the generation countermeasure network,and the generative adversarial network(GAN)model with local controllable generation is built to realize the directional generation of insulator belt defect samples.The experimental results show that the samples obtained by this method are improved in a number of quality indicators,and the quality effect of the samples obtained is excellent,which has a reference value for the data expansion of insulator images. 展开更多
关键词 Data expansion Deep learning Generate confrontation network insulator
下载PDF
A Simple and Effective Surface Defect Detection Method of Power Line Insulators for Difficult Small Objects
5
作者 Xiao Lu Chengling Jiang +2 位作者 Zhoujun Ma Haitao Li Yuexin Liu 《Computers, Materials & Continua》 SCIE EI 2024年第4期373-390,共18页
Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable... Insulator defect detection plays a vital role in maintaining the secure operation of power systems.To address the issues of the difficulty of detecting small objects and missing objects due to the small scale,variable scale,and fuzzy edge morphology of insulator defects,we construct an insulator dataset with 1600 samples containing flashovers and breakages.Then a simple and effective surface defect detection method of power line insulators for difficult small objects is proposed.Firstly,a high-resolution featuremap is introduced and a small object prediction layer is added so that the model can detect tiny objects.Secondly,a simplified adaptive spatial feature fusion(SASFF)module is introduced to perform cross-scale spatial fusion to improve adaptability to variable multi-scale features.Finally,we propose an enhanced deformable attention mechanism(EDAM)module.By integrating a gating activation function,the model is further inspired to learn a small number of critical sampling points near reference points.And the module can improve the perception of object morphology.The experimental results indicate that concerning the dataset of flashover and breakage defects,this method improves the performance of YOLOv5,YOLOv7,and YOLOv8.In practical application,it can simply and effectively improve the precision of power line insulator defect detection and reduce missing detection for difficult small objects. 展开更多
关键词 insulator defect detection small object power line deformable attention mechanism
下载PDF
Higher-order topological Anderson insulator on the Sierpiński lattice
6
作者 陈焕 刘峥嵘 +1 位作者 陈锐 周斌 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第1期218-222,共5页
Disorder effects on topological materials in integer dimensions have been extensively explored in recent years. However, its influence on topological systems in fractional dimensions remains unclear. Here, we investig... Disorder effects on topological materials in integer dimensions have been extensively explored in recent years. However, its influence on topological systems in fractional dimensions remains unclear. Here, we investigate the disorder effects on a fractal system constructed on the Sierpiński lattice in fractional dimensions. The system supports the second-order topological insulator phase characterized by a quantized quadrupole moment and the normal insulator phase. We find that the second-order topological insulator phase on the Sierpiński lattice is robust against weak disorder but suppressed by strong disorder. Most interestingly, we find that disorder can transform the normal insulator phase to the second-order topological insulator phase with an emergent quantized quadrupole moment. Finally, the disorder-induced phase is further confirmed by calculating the energy spectrum and the corresponding probability distributions. 展开更多
关键词 fractal system topological insulator
下载PDF
Three-dimensional topological crystalline insulator without spin-orbit coupling in nonsymmorphic photonic metacrystal
7
作者 Zhide Yu Lingbo Xia 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第10期282-286,共5页
By including certain point group symmetry in the classification of band topology,Fu proposed a class of threedimensionaltopological crystalline insulators(TCIs)without spin-orbit coupling in 2011.In Fu’s model,surfac... By including certain point group symmetry in the classification of band topology,Fu proposed a class of threedimensionaltopological crystalline insulators(TCIs)without spin-orbit coupling in 2011.In Fu’s model,surface states(ifpresent)doubly degenerate atГandM when time-reversal and C_(4) symmetries are preserved.The analogs of Fu’s modelwith surface states quadratically degenerate atM are widely studied,while surface states with quadratic degeneracy atГare rarely reported.In this study,we propose a three-dimensional TCI without spin-orbit coupling in a judiciously designednonsymmorphic photonic metacrystal.The surface states of photonic TCIs exhibit quadratic band degeneracy in the(001)surface Brillouin zone(BZ)center(Гpoint).The gapless surface states and their quadratic dispersion are protected by C4and time-reversal symmetries,which correspond to the nontrivial band topology characterized by Z_(2)topological invariant.Moreover,the surface states along lines fromГto the(001)surface BZ boundary exhibit zigzag feature,which is interpretedfrom symmetry perspective by building composite operators constructed by the product of glide symmetries with timereversalsymmetry.The metacrystal array surrounded with air possesses high order hinge states with electric fields highlylocalized at the hinge that may apply to optical sensors.The gapless surface states and hinge states reside in a cleanfrequency bandgap.The topological surface states emerge at the boundary of the metacrystal and perfect electric conductor(PEC),which provide a pathway for topologically manipulating light propagation in photonic devices. 展开更多
关键词 topological crystalline insulator nonsymmorphic photonic metacrystal
下载PDF
Thermal Performance Analysis of Plaster Reinforced with Raffia Vinifera Particles for Use as Insulating Materials in Building
8
作者 Etienne Malbila Danielle Manuella Djouego Tagne +3 位作者 Bouto Kossi Imbga Lareba Adelaide Ouedraogo Sié Kam David Yemboini Kader Toguyeni 《Journal of Minerals and Materials Characterization and Engineering》 2024年第2期112-138,共27页
The present study focuses on the formulation of new composite consisting of plaster and raffia vinifera particle (RVP) with the purpose to reducing energy consumption. The aim of this study is to test this new compoun... The present study focuses on the formulation of new composite consisting of plaster and raffia vinifera particle (RVP) with the purpose to reducing energy consumption. The aim of this study is to test this new compound as an insulating eco-material in building in a tropical climate. The composites samples were developed by mixing plaster with raffia vinifera particles (RVP) using three different sizes (1.6 mm, 2.5 mm and 4 mm). The effects of four different RVP incorporations rates (i.e., 0wt%, 5wt%;10wt%;15wt%) on physical, thermal, mechanicals properties of the composites were investigated. In addition, the use of the raffia vinifera particles and plaster based composite material as building envelopes thermal insulation material is studied by the habitable cell thermal behavior instrumentation. The results indicate that the incorporation of raffia vinifera particle leads to improve the new composite physical, mechanical and thermal properties. And the parametric analysis reveals that the sampling rate and the size of raffia vinifera particles are the most decisive factor to impact these properties, and to decreases in the thermal conductivity which leads to an improvement to the thermal resistance and energy savings. The best improvement of plaster composite was obtained at the raffia vinifera particles size between 2.5 and 4.0 mm loading of 5wt% (C95P5R) with a good ratio of thermo-physical-mechanical properties. Additionally, the habitable cell experimental thermal behavior, with the new raffia vinifera particles and plaster-based composite as thermal insulating material for building walls, gives an average damping of 4°C and 5.8°C in the insulated house interior environment respectively for cold and hot cases compared to the outside environment and the uninsulated house interior environment. The current study highlights that this mixture gives the new composite thermal insulation properties applicable in the eco-construction of habitats in tropical environments. 展开更多
关键词 Fibres PLASTER Thermal Test Mechanical Test Insulating Material Indoor Comfort
下载PDF
Estimation of pulsed laser-induced single event transient in a partially depleted silicon-on-insulator 0.18-μm MOSFET 被引量:6
9
作者 毕津顺 曾传滨 +3 位作者 高林春 刘刚 罗家俊 韩郑生 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期631-635,共5页
In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal-oxide-semiconductor (MOS) devices irradiated by pulsed laser beams. Transient sig... In this paper, we investigate the single event transient (SET) occurring in partially depleted silicon-on-insulator (PDSOI) metal-oxide-semiconductor (MOS) devices irradiated by pulsed laser beams. Transient signal characteristics of a 0.18-p.m single MOS device, such as SET pulse width, pulse maximum, and collected charge, are measured and an- alyzed at wafer level. We analyze in detail the influences of supply voltage and pulse energy on the SET characteristics of the device under test (DUT). The dependences of SET characteristics on drain-induced barrier lowering (DIBL) and the parasitic bipolar junction transistor (PBJT) are also discussed. These results provide a guide for radiation-hardened deep sub-micrometer PDSOI technology for space electronics applications. 展开更多
关键词 laser test single event transient charge collection partially depleted silicon on insulator
下载PDF
Reduced graphene oxide aerogel decorated with Mo_(2)C nanoparticles toward multifunctional properties of hydrophobicity,thermal insulation and microwave absorption 被引量:3
10
作者 Yahui Wang Minghui Zhang +5 位作者 Xuesong Deng Zhigang Li Zongsheng Chen Jiaming Shi Xijiang Han Yunchen Du 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第3期536-547,共12页
Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior micr... Reduced graphene oxide(rGO)aerogels are emerging as very attractive scaffolds for high-performance electromagnetic wave absorption materials(EWAMs)due to their intrinsic conductive networks and intricate interior microstructure,as well as good compatibility with other electromagnetic(EM)components.Herein,we realized the decoration of rGO aerogel with Mo_(2)C nanoparticles by sequential hydrothermal assembly,freeze-drying,and high-temperature pyrolysis.Results show that Mo_(2)C nanoparticle loading can be easily controlled by the ammonium molybdate to glucose molar ratio.The hydrophobicity and thermal insulation of the rGO aerogel are effectively improved upon the introduction of Mo_(2)C nanoparticles,and more importantly,these nanoparticles regulate the EM properties of the rGO aerogel to a large extent.Although more Mo_(2)C nanoparticles may decrease the overall attenuation ability of the rGO aerogel,they bring much better impedance matching.At a molar ratio of 1:1,a desirable balance between attenuation ability and impedance matching is observed.In this context,the Mo_(2)C/r GO aerogel displays strong reflection loss and broad response bandwidth,even with a small applied thickness(1.7 mm)and low filler loading(9.0wt%).The positive effects of Mo_(2)C nanoparticles on multifunctional properties may render Mo_(2)C/r GO aerogels promising candidates for high-performance EWAMs under harsh conditions. 展开更多
关键词 Mo_(2)C/reduced graphene oxide aerogel microwave absorption dielectric loss HYDROPHOBICITY thermal insulation
下载PDF
Ultra-low temperature radio-frequency performance of partially depleted silicon-on-insulator n-type metal-oxide-semiconductor field-effect transistors with tunnel diode body contact structures
11
作者 吕凯 陈静 +3 位作者 黄瑜萍 刘军 罗杰馨 王曦 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第11期652-655,共4页
Radio-frequency(RF) characteristics under ultra-low temperature of multi-finger partially depleted silicon-oninsulator(PD SOI) n-type metal-oxide-semiconductor field-effect transistors(nMOSFETs) with tunnel diod... Radio-frequency(RF) characteristics under ultra-low temperature of multi-finger partially depleted silicon-oninsulator(PD SOI) n-type metal-oxide-semiconductor field-effect transistors(nMOSFETs) with tunnel diode body-contact(TDBC) structure and T-gate body-contact(TB) structure are investigated in this paper.When operating at 77 K,TDBC device suppresses floating-body effect(FBE) as well as the TB device.For TB device and TDBC device,cut-off frequency(fT) improves as the temperature decreases to liquid-helium temperature(77 K) while that of the maximum oscillation frequency(/max) is opposite due to the decrease of the unilateral power gain.While operating under 77 K,fT and f(max) of TDBC device reach to 125 GHz and 77 GHz,representing 8%and 15% improvements compared with those of TB device,respectively,which is mainly due to the lower parasitic resistances and capacitances.The results indicate that TDBC SOI MOSFETs could be considered as promising candidates for analog and RF applications over a wide range of temperatures and there is immense potential for the development of RF CMOS integrated circuits for cryogenic applications. 展开更多
关键词 depleted immense representing tunnel partially finger floating analog helium insulator
下载PDF
Pressure induced insulator to metal transition in quantum spin liquid candidate NaYbS_(2)
12
作者 贾雅婷 龚春生 +6 位作者 李芷文 刘以轩 赵建发 王哲 雷和畅 于润泽 靳常青 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期369-372,共4页
Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of ... Pressure induced insulator to metal transition followed by the appearance of superconductivity has been observed recently in inorganic quantum spin liquid candidate NaYbSe_(2).In this paper,we study the properties of isostructural compound NaYbS_(2)under pressure.It is found that the resistance of Na YbS_(2)single crystal exhibits an insulating state below 82.9 GPa,but with a drop of more than six orders of magnitude at room temperature.Then a minimum of resistance is observed at about 100.1 GPa and it moves to lower temperature with further compression.Finally,a metallic state in the whole temperature range is observed at about 130.3 GPa accompanied by a non-Fermi liquid behavior below 100 K.The insulator to metal transition,non-monotonic resistance feature and non-Fermi liquid behavior of NaYbS_(2)under pressure are similar to those of NaYbSe_(2),suggesting that these phenomena might be the universal properties in NaLnCh_(2)(Ln=rare earth,Ch=O,S,Se)system. 展开更多
关键词 high pressure quantum spin liquid insulator to metal transition NaYbS_(2)
下载PDF
Thermal Hall effect and the Wiedemann–Franz law in Chern insulator
13
作者 王安新 秦涛 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第10期579-584,共6页
Thermal Hall effect, where a transverse temperature difference is generated by implementing a longitudinal temperature gradient and an external magnetic field in the perpendicular direction to systems, is a useful too... Thermal Hall effect, where a transverse temperature difference is generated by implementing a longitudinal temperature gradient and an external magnetic field in the perpendicular direction to systems, is a useful tool to reveal transport properties of quantum materials. A systematic study of the thermal Hall effect in a Chern insulator is still lacking. Here,using the Landauer–Büttiker formula, we investigated the thermal Hall transport of the Harper–Hofstadter model with flux φ= 1/2 and its generalizations. We demonstrated that the Wiedemann–Franz law, which states that the thermal Hall conductivity is linearly proportional to the quantum Hall conductivity in the low temperature limit, is still valid in this Chern insulator, and that the thermal Hall conductivity can be used to characterize the topological properties of quantum materials. 展开更多
关键词 thermal Hall effect quantum Hall effect Chern insulator Landauer–Büttike formula
下载PDF
Measurement of alumina film induced ablation of internal insulator in solid rocket environment
14
作者 Ji-Yeul Bae In Sik Hwang Yoongoo Kang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第11期181-192,共12页
This study investigates the ablation of internal insulation induced by the deposition of an alumina film with different lateral film speeds.A sub-scale test solid rocket motor(SRM)was designed in an impinging jet conf... This study investigates the ablation of internal insulation induced by the deposition of an alumina film with different lateral film speeds.A sub-scale test solid rocket motor(SRM)was designed in an impinging jet configuration to form an alumina film on the sample and to encourage the lateral movement of the film by a high-speed wall jet.Fifteen static fire tests of the test SRM were conducted with six different jet velocities(V_(jet)=100 m/s,150 m/s,200 m/s,268 m/s,330 m/s,and 450 m/s)that indirectly affected the velocity of the wall jet and the deposition rate of alumina droplets.The ablation velocity was deduced from the difference in the sample thickness after a test using a coordinate measuring machine.The droplet deposition mass flux and wall jet velocity were obtained via two-phase flow simulation with the same jet velocity and effective pressure.As a result,the characteristics of alumina-induced ablation and the changes in ablation with jet velocities were obtained.The area within0.8×jet diameter was focused upon,where the ratio of ablation velocity to incoming alumina mass was constant for each jet velocity,and showed a similarity in jet structure.When the ablation velocity was increased from 2.05 to 9.98 mm/s with increasing jet velocity,the ratio of the ablation velocity and alumina mass flux decreased from 1.07×10^(-4)to 0.49×10^(-4)m^(3)/kg as Al_(2)O_(3)-C reactions became less efficient with a reduced residence time of the film.Because the decrease in residence time by the wall jet is more pronounced for slow reactions involved in Al_(2)O_(3)-C reactions,fast reactions in Al_(2)O_(3)-C reactions are less affected and result in a convergence of the volumetric rate of ablation per unit mass of alumina. 展开更多
关键词 Internal insulation Solid rocket motor Ablation ALUMINA
下载PDF
Numerical Simulation of Contamination Accumulation Characteristics of Composite Insulators in Salt Fog Environment
15
作者 Yukun Lv Zeze Chen +2 位作者 Quanzhi Ge Qian Wang Yazhao Zhang 《Energy Engineering》 EI 2023年第2期483-499,共17页
To investigate the fouling characteristics of the composite insulator surface under the salt fog environment,the FXBW-110/120-2 composite insulator was taken as the research object.Based on the field-induced charge me... To investigate the fouling characteristics of the composite insulator surface under the salt fog environment,the FXBW-110/120-2 composite insulator was taken as the research object.Based on the field-induced charge mechanism,the multi-physical field coupling software COMSOL was used to numerically simulate the fouling characteristics,explored the calculation method of ESDD,and demonstrated its rationality.Based on this method,the pollution characteristics of the composite insulator under the pollution fog environment were studied,and the influence of wind speed,droplet size,and voltage type on the pollution characteristics of the composite insulator was analyzed.The results showed that:with the increase in wind speed,the amount of accumulated pollution of insulator increases in the range of droplet size,and the relationship between wind speed and accumulated pollution is approximately linear;at the same wind speed,the amount of accumulated pollution increases with the increase of droplet size under the action of DC voltage;when there is no voltage,the amount of dirt on the upper surface of the insulator is more than that on the lower surface,while it is the opposite under DC voltage. 展开更多
关键词 Composite insulator numerical simulation fouling characteristics equivalent salt deposit density salt fog environment
下载PDF
Magneto-optical Kerr and Faraday effects in bilayer antiferromagnetic insulators
16
作者 朱婉情 单文语 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第8期472-478,共7页
Control and detection of antiferromagnetic topological materials are challenging since the total magnetization vanishes.Here we investigate the magneto-optical Kerr and Faraday effects in bilayer antiferromagnetic ins... Control and detection of antiferromagnetic topological materials are challenging since the total magnetization vanishes.Here we investigate the magneto-optical Kerr and Faraday effects in bilayer antiferromagnetic insulator Mn Bi2Te4.We find that by breaking the combined mirror symmetries with either perpendicular electric field or external magnetic moment,Kerr and Faraday effects occur.Under perpendicular electric field,antiferromagnetic topological insulators(AFMTI)show sharp peaks at the interband transition threshold,whereas trivial insulators show small adjacent positive and negative peaks.Gate voltage and Fermi energy can be tuned to reveal the differences between AFMTI and trivial insulators.We find that AFMTI with large antiferromagnetic order can be proposed as a pure magneto-optical rotator due to sizable Kerr(Faraday)angles and vanishing ellipticity.Under external magnetic moment,AFMTI and trivial insulators are significantly different in the magnitude of Kerr and Faraday angles and ellipticity.For the qualitative behaviors,AFMTI shows distinct features of Kerr and Faraday angles when the spin configurations of the system change.These phenomena provide new possibilities to optically detect and manipulate the layered topological antiferromagnets. 展开更多
关键词 magneto-optical Kerr and Faraday effects antiferromagnetic topological insulators bilayer systems
下载PDF
Effect of electrodes and thermal insulators on grain refinement by electric current pulse 被引量:5
17
作者 尹振兴 梁冬 +2 位作者 陈玉娥 程誉锋 翟启杰 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2013年第1期92-97,共6页
The application of electric current pulse(ECP) to a solidification process refers to the immersion of electrodes into the liquid metal and the employment of thermal insulators on the upper surface of metal.In order ... The application of electric current pulse(ECP) to a solidification process refers to the immersion of electrodes into the liquid metal and the employment of thermal insulators on the upper surface of metal.In order to ascertain the effects of these two factors on the structure refinement by the ECP technique,three groups of experiments were performed with different types of electrodes or various thermal insulators.By the comparison between solidification structures under different conditions,it is followed that the electrode and the thermal insulator have an obvious influence on the grain refinement under an applied ECP,and further analysis demonstrates that the thermal conditions of the liquid surface play a vital role in the modification of solidification structure.Also,the results support the viewpoint that most of the equiaxed grains originate from the liquid surface subjected to an ECP. 展开更多
关键词 solidification structure grain refinement electric current pulse electrode thermal insulator
下载PDF
A Novel Insulator and Its Characteristics 被引量:2
18
作者 李晓峰 J.M.K.MacAlpine +3 位作者 陈俊武 王燕 张国胜 李正瀛 《Journal of Southeast University(English Edition)》 EI CAS 2001年第2期47-51,共5页
Both the ceramic and the composite insulators have their own advantages and disadvantages when compared with each other. It is a reasonable idea to combine their merits together to design a novel insulator. The key me... Both the ceramic and the composite insulators have their own advantages and disadvantages when compared with each other. It is a reasonable idea to combine their merits together to design a novel insulator. The key measure of the novel insulator suggested in this paper is to add an annular metal sheet coated with high temperature vulcanisation (HTV) silicone rubber (SIR) at the base of the traditional ceramic insulator cap. The HTVSIR covering on the exterior of the metal sheet can lengthen the creepage distance. The metal sheet can uniform the electric stress, reduce its maximum value and modify its direction on one insulator unit and acts as equalizing ring on an insulator string. The factors stated above are the main reasons why the novel insulator has better insulating performance, including lower leakage current and flashover voltage, especially under polluted conditions. Simultaneously, the novel insulator can overcome the disadvantages of the ordinary remedies which have been widely used to improve the performance of ceramic insulators against pollution. The experimental results obtained in the laboratory were in good agreement with the theoretical analysis and demonstrated the novel insulator's effectiveness. 展开更多
关键词 novel insulator leakage current pollution flashover HTVSIR
下载PDF
Drain and Source on Insulator MOSFETs Fabricated by Local SIMOX Technology 被引量:1
19
作者 何平 江波 +6 位作者 林曦 刘理天 田立林 李志坚 董业明 陈猛 王曦 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2003年第6期592-597,共6页
To overcome the floating-body effect and self-heating effect of SOI devices,the drain and source on insulator (DSOI) structure is fabricated and tested.The low dose developed recently and low energy local SIMOX techno... To overcome the floating-body effect and self-heating effect of SOI devices,the drain and source on insulator (DSOI) structure is fabricated and tested.The low dose developed recently and low energy local SIMOX technology combined with the conventional CMOS technology is used to fabricate this kind of devices.Using this method,DSOI,SOI,and bulk MOSFETs are successfully integrated on a single chip.Test results show that the drain induced barrier lowering effect is suppressed.The breakdown voltage drain-to-source is greatly increased for DSOI devices due to the elimination of the floating-body effect.And the self-heating effect is also reduced and thus the reliability increased.At the same time,the advantage of SOI devices in speed is maintained.The technology makes it possible to integrate low voltage,low power,low speed SOI devices or high voltage,high power,high speed DSOI devices on one chip and it offers option for developing system-on-chip technology. 展开更多
关键词 SIMOX MOS devices silicon on insulator technology floating-body effect
下载PDF
Highly Porous Yet Transparent Mechanically Flexible Aerogels Realizing Solar-Thermal Regulatory Cooling 被引量:1
20
作者 Meng Lian Wei Ding +5 位作者 Song Liu Yufeng Wang Tianyi Zhu Yue-EMiao Chao Zhang Tianxi Liu 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第7期231-243,共13页
The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fab... The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fabricated through filtration-induced delaminated gelation and ambient drying.The delaminated gelation process involves the assembly of fluorinated cellulose nanofiber(FCNF)at the solid-liquid interface between the filter and the filtrate during filtration,resulting in the formation of lamellar FCNF hydrogels with strong intra-plane and weak interlayer hydrogen bonding.By exchanging the solvents from water to hexane,the hydrogen bonding in the FCNF hydrogel is further enhanced,enabling the formation of the DAF with intra-layer mesopores upon ambient drying.The resulting aerogel film is lightweight and ultra-flexible,which pos-sesses desirable properties of high visible-light transmittance(91.0%),low thermal conductivity(33 mW m^(-1) K^(-1)),and high atmospheric-window emissivity(90.1%).Furthermore,the DAF exhibits reduced surface energy and exceptional hydrophobicity due to the presence of fluorine-containing groups,enhancing its durability and UV resistance.Consequently,the DAF has demonstrated its potential as solar-thermal regulatory cooling window materials capable of simultaneously providing indoor lighting,thermal insulation,and daytime radiative cooling under direct sunlight.Significantly,the enclosed space protected by the DAF exhibits a temperature reduction of 2.6℃ compared to that shielded by conventional architectural glass. 展开更多
关键词 Transparent aerogel Cellulose nanofiber aerogel Delaminated gelation Thermal insulation Passive daytime radiative cooling
下载PDF
上一页 1 2 68 下一页 到第
使用帮助 返回顶部